According to law enforcement sources cited by ABC, however, the "suspicious behavior" in that case turned out to be two people "making out" in the bathroom. [...]

An FBI statement on the incident, however, mentions neither "making out" nor "intimate relations." It says simply, "Out of an abundance of caution, NORAD scrambled F-16 jets to shadow the flight until it landed safely at DTW at approximately 3:30 PM EDT. Law enforcement met the flight, which was brought to a remote area of the airport. The plane was swept with negative findings and cleared at 5:15 PM ET."